Choosing Your AR15 Fighting Rifle

Last Updated 13 February 2017

I frequently get asked about AR15’s. Specifically, people want to know which one to buy. It makes sense: I believe every American should own a quality duty pistol and a semiautomatic fighting rifle. According to some sources, the AR15 is the single most popular gun in America. It’s no surprise how it got there: it’s lightweight, accurate, extremely reliable, and infinitely customizable. Without a doubt, the AR15 is my favorite gun.

There are literally thousands of different configurations of the AR15 produced by scores of manufacturers. But it would be folly to assume that all AR’s are created equal. They are certainly not. In this post, I plan to show you how to choose your first AR15. I hope to help you wade through the infinite possibilities and narrow things down to the best options for you, the Armed Citizen.

Some Assumptions

The first thing you need to do when you decide to buy an AR is ask yourself what you intend to use it for. Mission drives gear; the gear doesn’t drive the mission. I’m going to go into this with the assumption that the AR15 you’re buying is for “general purpose” fighting use. What exactly do I mean by that?

You can set up an AR15 for all kinds of specialist roles. Highly accurized AR’s may be used for varmint hunting, competition, or as squad designated marksman rifles. Other AR’s might be built for 3-gun or other action shooting sports. Some might have super-heavy barrels for benchrest shooting.

When I say a general purpose fighting rifle, I mean a rifle that is set up like an infantryman’s rifle. It’s built for reliability and durability above all. I’m talking about a rifle that will suffice for the roles of home defense, training, hunting, or competition. I mean a gun that is easy to handle, relatively lightweight, and which can be used effectively from bad breath distance all the way out to 300+ yards.

Another assumption I’m going to make is that you’re not looking to waste your money on a piece of junk. You may or may not be interested in spending a ton of money, but you have to understand that all manufacturers are NOT created equal. Most of them don’t make their rifles to the appropriate specification. I’ll go into more detail about this later, but for now let’s just assume that you want a gun built to the proper spec (trust me, you do).

Choosing Your Caliber

There are a lot of awesome caliber choices out there for the AR, and almost all of them would be appropriate for the general purpose fighting gun I’m writing about now. .308, .300 AAC Blackout, 6.8 SPC – those are all great rounds that would perform well in that general purpose role. But I’m going to recommend that when choosing a caliber for your AR15, you stick with the old standby: the 5.56×45 NATO (aka: .223 Remington). The reasons for this are pretty straightforward.

First of all, despite the number of internet keyboard commandos who say otherwise, the 5.56 is plenty powerful enough for social purposes. Trust me: the US military and its allies have killed a lot of people with 5.56. It’s not the wimpy poodle-shooter that many armchair experts claim it is.

Secondly, as a smaller round, it has less of all the bad things that come with a bigger round: recoil, weight, sound, blast, etc. An AR15 chambered in 5.56 can be easily handled by anybody in your family. Children, women, and small adults all have fun shooting the 5.56. If you aspire to be a Level 3 Armed Citizen, then the weight savings will also appeal to you.

Third: Cost and availability. As awesome as the .300 AAC Blackout is (it might be my favorite caliber in theory), I don’t own a gun chambered for it because it’s just too dang expensive. Even practice ammo for the .308 or .300 AAC can cost more than $0.50/round – even as much as $0.75/round. On the other hand, quality 5.56 training ammo can easily be had for less than $0.35/round. Getting ammo that costs half as much as other rounds means that you can train twice as much. 5.56 is also pretty readily available. The same can’t be said for some of those other specialty rounds.

Construction of Your AR15

The term “Mil-Spec” gets thrown around a lot when it comes to to AR15’s. In fact, it often gets used by manufacturers who DO NOT build their guns to anything resembling the military specification for M4’s and M16’s. In my opinion, this is THE MOST IMPORTANT factor in buying a good AR15.

When I use the term “Mil-Spec”, what I mean is a rifle that gets built to the following list of standards:

• High Pressure Tested (HPT) Bolt and Barrel
• Magnetic Particle Inspected (MPI) Bolt and Barrel
• Barrel Steel: Either Mil-Spec 11595E or 4150
• Chrome-lined (or nitrided) barrel
• Shot-peened bolt
• A properly staked gas key
• M4 feed ramps
• 5.56 NATO chamber (NOT a .223 chamber – there is a difference)

I won’t go into depth on what each of those features mean. If you’re curious about a particular one, then just search the web for that term and you’ll be able to read all about it. Here is what you need to understand about those Mil-Spec features: a properly built AR15 should have all those features. I personally wouldn’t buy one that didn’t have all those things. Choose your AR15 manufacturer accordingly.

Understand that I am NOT telling you that your Bushmaster or DPMS gun is just a piece of garbage. It is has worked well for you, then that’s awesome. Keep on trucking. But what I am telling you is that 99 times out of 100, a gun built by, say for example, Bravo Company is going to work better and last longer than your non-Mil-Spec gun. 

The best thing to do is to just stick with a reputable manufacturer known for high quality control and Mil-Spec construction. My personal favorite is Bravo Company. Daniel Defense is also good, and if I’m on a budget, I would go with Spike’s Tactical. Those aren’t the only three manufacturers that make Mil-Spec guns, but you can probably find whatever you want being sold by one of them.

Barrel and Gas System Configuration

The next big decision point for you is exactly what barrel and gas system to get. I will try to make this as simple as I can. 

For a general purpose fighting AR, there are really only two (well, three… kind of) barrel lengths I would consider: a 16″ barrel or a 14.5″ barrel (or 14.7″). The reason I recommend those is that they are the shortest barrel lengths you can readily get without having to do the NFA paperwork and make a SBR (short-barreled rifle).

I personally like the handling of a 14.5″ gun better than a 16″ one, but it will be just a little more pricey because you have to get a longer-than-normal flash hider permanently welded onto the muzzle in order to make it legal. A 14.7″ barrel works the same way except that you can permanently weld a standard flash hider on there instead of a longer-than-normal one.

As for gas system, there’s only one real choice in any of those particular barrel lengths: the mid-length (or middy) gas system. Without going into a big physics lesson, just understand that the middy is longer than a normal carbine-length gas system. Because it’s longer, you will reap a whole host of benefits which include lower recoil, greater reliability, lower operating temperatures/pressures, and longer sight radius. There’s really no reason to get anything other than a middy when buying a 16″ or 14.5″ gun.

Rail or No Rail?

Your next big decision point will be whether or not you choose to buy a rail system for your AR15. If you have the money, then a quality rail is a good thing to have, but it’s certainly not necessary. I have both railed and non-railed uppers, myself.

There are a lot of cheap rails out there, but they usually don’t free-float the barrel. Honestly, while cheap rails may work, they really just end up being like heavier, more expensive versions of a good plastic handguard. If you’re going to get a rail, then get a good one. Daniel Defense makes good rails, but my absolute favorite rail is the Bravo Company KMR-A rail. It’s slim, super lightweight, very strong, and it free-floats the barrel. The Keymod attachment system reduces the bulk and weight as well as making the rail more comfortable in the hand. If using a rail, then I really like to get an extra long one. Extra long rails give you more options and a longer sight radius when using iron sights. On my guns (both 14.5″ and 16″), I use 13″ rails.

If you decide not to get a rail, then there is only one plastic handguard worth buying: the Magpul MOE M-LOK Mid-Length Handguard. The MOE handguard is a quality piece and the M-LOK attachment system means you can add lights and sling mounts to it as if it were a rail. You can even put a vertical fore grip on there, but I don’t know why you would.

Everything Else – Triggers, Stocks, Lowers, Sights, Pistol Grips, Muzzle Devices

As long as you meet the above recommendations, everything else is gravy.

As far as lower receivers and stocks and such, just understand that most AR15 lowers are all pretty similar. They’re just machined blocks of aluminum. As long as you get a quality Mil-Spec lower parts kit, then the brand stamped on the lower itself doesn’t really matter all that much. These days, my favorite thing to do is just buy a stripped lower and a parts kit and put it together yourself. It doesn’t require many tools at all (a screwdriver and a pair of channel locks will do), and it only takes about 30-45 minutes. You can find plenty of videos on YouTube demonstrating how to put one together.

You do, however, need to get a quality Mil-Spec lower parts kit. I don’t recommend going with any kind of match trigger setup for your general purpose rifle – definitely not until you’ve learned to use the thing by putting a few thousand rounds through it. I’m okay with the “enhanced standard triggers” like the BCM PNT trigger or the ALG Defense Triggers. But save your money and skip on the really high-end match grade triggers. Most of them have no place in a fighting gun (there are some exceptions, like the Geissele SSA).

My favorite stock is the BCM Gunfighter stock, but any regular old collapsible stock is fine. I like the BCM stock because it locks up solid and has a really grippy rubber pad on the butt. I’m also a big fan of the BCM Gunfighter pistol grip, but any pistol grip will do. The enlarged trigger guards are also a nice-to-have feature. Those sort of things are really just individual preference, though.

Same thing for charging handles. I personally like the BCM Gunfighter Charging Handle w/ Mod 4 Latch, but any charging handle will work.

While there are some good muzzle brakes and compensators out there, I’m still an A2-style birdcage flash hider kind of guy. Brakes and comps increase the noise, blast, and flash. Some strike a good balance between recoil reduction and noise/blast/flash, but the recoil of a 5.56 round in a 16″ or 14.5″ middy is so light anyway that I would just rather have the noise and flash reduction of the old birdcage.

As for sights: I love optics, and there are all kinds of options there, but optic selection merits its own post. What I will tell you for now is to get iron sights. Even if you have an optic, you will want backup irons. This is another preference thing. You can spend as little as $80 for a set of polymer Magpul “iron” sights or as much as $220 for good steel Troy sights. I always get the kind that fold down because I have optics on all my guns.

So How About Some Examples?

Also, remember that a stylish gunfighter always accessorizes! That thing does you no good without plenty of magazines (I recommend at least 10 good ones) and lots of ammo (buy a case of 1000 rounds to start). A good two-point sling and some kind of load-carrying gear are excellent additions, as well.

And don’t forget the most important part of all of this: training. If you’re going to pick up one of these rifles and you plan to use it to defend yourself, then come out to ATA and learn how to do it right. ATA Rifle I is a great training experience and it will set you up for success. The only thing more fun than buying AR15’s is getting out and shooting them.

Click here to sign up for ATA Rifle I

Josh Bales is a Level 10 Paladin with an 18 in Charisma and over 100 Hit Points. He gained most of his XP by serving in the Marine Corps as an Infantry Officer, where he deployed to Afghanistan as a Rifle Platoon Commander. He has been training in combative shooting and tactics for the past 11 years, and teaching these topics for the past 8 years. He currently resides in Southeastern Kentucky where he spends time doing cardio, powerlifting, fighting fire, reading, and just generally training for the fight.